Solar modules (or panels) including solar thermal or solar photovoltaic (PV) modules are attracting a great deal of attention as they are able to generate clean renewable energy without causing an increase of atmospheric carbon dioxide or other dangerous green house gases and have thus a strong positive influence on the climatic balance in the atmosphere.
A variety of solar module structures for commercial and residential appliances have been proposed. For example, solar PV modules structures are typically constructed as an assembly of PV individual modules having layered structure including a packed interconnected assembly of photovoltaic elements, also known as solar PV cells. Said layered structure generally includes a substrate that can be for example made of metal or glass or possibly flexible supports, a semiconductor active layer disposed on said substrate, and a transparent and/or conductive layer disposed on said semiconductor active layer. Protective means are also generally needed in a PV module, to protect it from heat, humidity and from any possible environmental exposure or risk during transport. The solar thermal modules structures comprise typically a flow inlet and a flow outlet and ducts for circulating a diathermic fluid (water or other fluid) ensuring a well-determined heat-exchange surface exposed to the incident solar radiation.
Techniques have also been developed for ensuring assembly of individual PV cells or of solar panels in arrays, providing mechanical connection and enabling mounting on target substrates (roofs, walls, . . . ) for ensuring fast fixture and proper angle of inclination for the interception of solar radiation.
Generally solar panels have been assembled and fixed to substrates through the use of aluminum frame. Although aluminum is a relatively light metal, its weight nevertheless contributes significantly to the total weight of the assembly. Further, such aluminum frames are manufactured from profiles which should undergo significant machining/mounting/welding/assembling steps for providing the frame, with significant associated costs, and which might severely limit the range of shapes accessible. Still, aluminum being an electrical conductor, some current lost is possible, detrimentally affecting overall efficiency of the array of solar modules.
The need was felt thus for making available structural support for solar modules which can be easily manufactured, which are lightweight, electrically non-conductive, possessing outstanding thermal resistance, low coefficient of expansion appropriate mechanical stability and which are able to withstand the long run effects of wind, rain, or sun.
Structural supports for solar modules made from synthetic plastics have been proposed in the past.
Thus, U.S. Pat. No. 4,123,570 Feb. 6, 1979 discloses a support for solar cell array made from a lightweight high strength plastic material, and more particularly from a polyester or a polyepoxide reinforced with fibers including glass, boron and carbon fibers. Nevertheless, these supports might not be appropriate for complying with the requirements of maintaining properties in a wide range of operating temperatures, like those which a PV modules arrays can be exposed when mounted outdoor, during both winter cold periods (with temperatures well below 0° C.) and sunny summer periods (with peak temperatures possibly reaching 85° C.).
Similarly, US 20110030767 Oct. 2, 2011 discloses frames for PV modules made of particular polyurethane elastomers, possibly filled with reinforcing fillers and comprising fire retardants. However, in order to reach the final properties of said polyurethane materials, complex, time consuming manufacturing processes are needed.
Further, in addition, properties of single components of a solar panel, including structural frames, junction boxes, and the like, have been recognized as critical for achieving overall certification of the assembly, including notably with regards to their anti-flame features: all those ‘non-active’ parts have thus attracted increasing attention so as to ensure their compliance with highly demanding UL laboratories standards.
As a whole, there is thus still a continuous need for alternative materials for structural support for solar modules which can fulfil all above detailed requirements.